Cookie policy: This site uses cookies (small files stored on your computer) to simplify and improve your experience of this website. Cookies are small text files stored on the device you are using to access this website. For more information please take a look at our terms and conditions. Some parts of the site may not work properly if you choose not to accept cookies.

Join

Subscribe or Register

Existing user? Login

Why patients on lithium need attention

A BNF case study that reminds pharmacists of the valuable role they have to play in preventing harm from lithium therapy

Woman on lithium therapy

A 28-year-old woman with a history of mania presents with a repeat prescription for 28 days’ supply of Priadel M/R tablets 400mg od.

She complains that she is feeling weak and cold. She has recently become constipated and is experiencing heavy menstrual bleeding. Further conversation reveals that her blood was last tested by a psychiatric unit over seven months ago.

She does not display any symptoms of mania and has not had a relapse since her initial hospital admission. Her patient medication record shows that she has been taking Priadel for over a year. You decide to speak to her GP.

Which laboratory parameters will you ask the GP to measure?

According to the prescribing notes for lithium (section 4.2.3, BNF 60), long-term use of this drug has been associated with thyroid disorders, with women at greater risk of hypothyroidism than men. This patient’s symptoms should alert you to the possibility of lithium-induced hypothyroidism.

Because she is receiving long-term treatment with lithium, thyroid and renal function should be monitored every six months or more frequently if there is evidence of deterioration. Renal function should also be monitored more frequently if there are other risk factors, such as starting angiotensin-converting enzyme inhibitors, non-steroidal anti-inflammatory drugs or diuretics.

Serum lithium concentration should be monitored weekly on initiation of treatment or following dose changes, and every three months once levels are stable. If this patient is confirmed to be hypothyroid, the management of her mania will have to be reviewed.

If lithium-induced hypothyroidism is confirmed, an alternative treatment should be considered for her mania because the hypothyroidism is reversible if lithium is withdrawn. If continued treatment with lithium is essential, the patient should be treated with levothyroxine.

What should the target range be for this patient’s serum lithium concentration?

Because she is receiving lithium maintenance therapy, this patient’s serum lithium concentration should be at the lower end of the range of 0.4–1mmol/L for a sample taken 12 hours after the preceding dose. It is important to determine the optimum range for each individual patient.

BNF 59Details

Adapted from BNF 59 Community e-Update, an e-learning module produced by the Centre for Pharmacy Postgraduate Education (CPPE) and the British National Formulary.

BNF 60 Community e-Update is now available online

Citation: The Pharmaceutical Journal URI: 11049610

Have your say

For commenting, please login or register as a user and agree to our Community Guidelines. You will be re-directed back to this page where you will have the ability to comment.

Recommended from Pharmaceutical Press

  • Disease Management

    Disease Management

    Disease Management covers the diseases commonly encountered in primary care by system, with common therapeutic issues. Includes case studies and self-assessment sections.

    £54.00Buy now
  • Developing Your Prescribing Skills

    Developing Your Prescribing Skills

    Developing Your Prescribing Skills uses case studies, mind maps and feedback from experienced prescribers. It supplies practical advice on the issues facing prescribers in all types of practice.

    £23.00Buy now
  • FASTtrack: Pharmaceutics - Dosage Form and Design

    FASTtrack: Pharmaceutics - Dosage Form and Design

    FASTtrack: Pharmaceutics – Dosage Form and Design removes the complexity from the major dosage forms that are commonly encountered by pharmacists in professional practice.

    £25.00Buy now
  • Clinical Pharmacy Pocket Companion

    Clinical Pharmacy Pocket Companion

    An A-Z pocket book containing concise and practical pharmaceutical information for busy clinical pharmacists.

    £33.00Buy now
  • Workplace Drug Testing

    Workplace Drug Testing

    Explains drug testing regulatory frameworks and all aspects of drug analysis. Case studies of successful programmes are included.

    £81.00Buy now

Search an extensive range of the world’s most trusted resources

Powered by MedicinesComplete
  • Print
  • Share
  • Comment
  • Save
  • Print Friendly Version of this pagePrint Get a PDF version of this webpagePDF

Newsletter Sign-up

Want to keep up with the latest news, comment and CPD articles in pharmacy and science? Subscribe to our free alerts.